In one prior art contact rail of this type, disclosed in DE-GM8715494, the contact rail is round in shape and consists of transparent plastic material.
Contact rails made of transparent plastic material have not been frequently used, in practice, since their stiffness and stability is insufficient. Furthermore, the optical characteristics of such transparent plastic rails are also insufficient. When glass fibers or other inlays are employed to increase the stability, the optical characteristics of such a contact rail are no longer satisfactory.